Survey, identification and pathogenicity of alternaria blight of Tomato

The study aimed to assess survey, isolation, identification and pathogenicity of the Alternaria alternata. Disease intensity varied from 46.6 to 55.7% in four surveyed districts of Rajasthan during summer 2017–18. The disease severity of Alternaria blight of tomato was more in Jaipur (55.75) district followed by Alwar (49.56), Dausa (48.45) and Tonk (46.63) district, Alternaria alternata isolated from infected samples of tomato leaves, purified and its pathogenicity was proved. The pathogen produced dark brown to black colony with septate mycelium and acro petal chain of ellipsoidal brown or muriform conidia.